Technical Field
The present invention relates to a composite substrate, in which a rigid substrate and a flexible substrate are joined together.
Background Art
A composite substrate formed by joining a rigid substrate to a flexible substrate that is flexible is widely used in various electronic devices. Many ways of joining a rigid substrate to a flexible substrate have been developed.
Patent Document 1 discloses a rigid-flexible printed circuit in which a flexible substrate is laminated on a rigid substrate, for example. Forming a cutout in the base substrate removes part of the base substrate, which makes it possible to prevent contamination by the residues from the base substrate.
Also, Patent Document 2 discloses a composite wiring substrate in which a flexible substrate is sandwiched between rigid substrates. Forming dummy vias in the rigid substrates allows equal pressure to be applied to the flexible substrate, thereby making it possible to prevent warping of the flexible substrate.